1. Field of the Invention
The invention relates to an evaluation system and method for quantitatively evaluating a workspace such as a workplace, a monitor room, a control room, or an office which is represented by a three-dimensional model.
2. Description of the Background Art
Conventionally, a monitor room for monitoring and controlling a power plant or a factory, an office where a number of word processors and the like are used, an operating room for a medical appliance such as a CT (Computed Tomography) scanner, or a moving facility such as an elevator, or an escalator installed in a public location is designed on the basis of sketches which show the interior of a room where desks, chairs, etc. are arranged and which are drawn by a designer from various viewpoints.
In a design of a monitor and control room, items to be checked include whether or not an operator sitting at a supervisor control panel can see a large screen on a wall without being obstructed by the control panel, and whether or not the accommodation feeling is sufficient. In a design of an operating room for a medical appliance, items to be checked include whether or not an operator can operate the appliance while seeing a patient, and whether or not a doctor can see a picked up image without hindering the motion of the operator.
The designer must draw sketches while considering these items to be checked. Furthermore, the designer must also consider that operators or supervisors are different in height. Particularly in the case of a medical appliance, not only a male operator but also a female operator operates it, and therefore such an appliance must correspond to a height range from 150 cm to 180 cm or more. Using sketches in a design, however, it is substantially impossible to check the items from arbitrary viewpoints.
In a design of a moving facility such as an elevator, conventional checks using sketches cannot permit judgement on whether or not an adult, a child, and a person using a wheelchair can select floor buttons without trouble, and whether or not there is a gap difference which may obstruct a movement of a wheelchair, in a passage from a gate to the elevator. Furthermore, in the method using sketches, it is impossible to judge whether or not a situation where only a child is on an escalator can be recognized from a place lower than the escalator. In the prior art method using sketches, furthermore, it is impossible to study the degree of inclination which is produced when a wheelchair is on a descending escalator, and the degree of a sensation of fear due to the inclination by a person in the wheelchair.
In addition to the above-mentioned items, items to be checked in a design further include important ones which cannot easily be judged in the method using sketches. For example, whether or not a child or a person using a wheelchair can see position indicator lamps of an elevator or the like, and what kinds of discomfort a child or a short person in a crowded elevator or train must endure (for example, the face is pressed against the back or long hair of another person).
In order to solve these problems in a design check using sketches, a design check using computer graphics has recently been conducted. In a design check using computer graphics, a CAD (Computer Aided Design) or the like is used in place of sketches, so that three-dimensional models of objects such as a supervisor control panel, a desk, and a chair are input to be arranged in a three-dimensional space. In computer graphics, a three-dimensional space can be seen as a perspective view in an arbitrary viewpoint. Using this feature, it is possible to check a design in an arbitrary viewpoint. Furthermore, it is being studied to employ the virtual reality (VR) technique wherein objects disposed in a three-dimensional space produced by computer graphics are moved by using a device such as a data glove which can indicate the shape of fingers and the three-dimensional position of a hand.
In such a position change according to the virtual reality, a supervisor control panel, a desk, and the like can be moved to an arbitrary position. However, it is impossible to clearly indicate the point in which the alternative arrangement obtained as a result of the position change is superior to other arrangements. There is nothing to qualitatively evaluate these arrangements by comparing perspective views on which these arrangements are shown as pictures.
In another method, a mock-up of a scale of 1/10 is produced, and views are picked up by a CCD (charge-coupled device) to verify actual views. Since the viewpoint cannot be moved to an arbitrary position and displays on a large screen must be imitated by drawings printed on papers, however, this method has a drawback that visibility or sight distance cannot be evaluated. With respect to a computer display screen, therefore, simulation for display evaluation is separately produced by a computer, and the evaluation is conducted on the basis of this simulation. In this way, works on a computer display screen and an actual workspace are separately evaluated.
On the other hand, in the field of the human factors or ergonomics, there is an analysis method in which an operator in the spot is observed, motions of the operator are recorded in the form of motion lines, and the analysis is conducted on the basis of the recorded motion lines. According to this method, motions peculiar to the operator can be analyzed. However, the method cannot anticipate differences in motion due to a body part size such as the height. When a short operator conducts a work, for example, a supervisor control panel obstructs the view of a large screen, resulting in that the operator must conduct motions of rising from and sitting on a chair more often than when an average-height operator conducts the same work. Moreover, for the workspace which is newly designed, there is no actual work place where such observation can be conducted. Therefore, this analysis method cannot be applied to such a workspace. In some cases, an actual-size model of a workspace is produced and so-called actual-size simulation is conducted by using the model. In such actual-size simulation, experiments must be conducted on many subjects of various body sizes, and therefore it is anticipated that it requires great expense. Accordingly, such actual-size simulation may be used in a large-scale design, but not in a small-scale design such as a design of a kitchen. In a workspace of a medical appliance, doctors are so busy that it is difficult to make the doctors join in actual-size simulation and obtain comments or suggestions from them. Similarly, it is difficult to make persons using a wheelchair and children take part in actual-size simulation and obtain comments from them.
In the field of the human factors, known are a keystroke-level model for anticipating a time required for a very skilled operator to operate a keyboard (Card, S. K., Moran, T. P., and Newell, A. (1980), "The keystroke-level model for user performance time with interactive systems," Communications of the ACM, 23, pp. 396-410), and a GOMS (Goals Operators Methods and Selection-rules) model for anticipating actions of a user conducted when editing a text (Card, S. K., Moran, T. P., and Newell, A. (1983), "The Psychology of Human Computer Interaction," Hillsdale, N.J.: Erlbaum).
These are models or evaluation methods for a very restricted portion of works which are conducted facing a computer. When an alternative of an arrangement of a workspace is to be comparatively evaluated, an evaluation model or an evaluation technique for all the works conducted in the whole workspace which include not only works conducted facing a computer but also document works conducted at the side of the computer, and works accompanied by movement of the body is required. Therefore, a conventional model or evaluation method cannot evaluate an alternative of an arrangement of a workspace.
In order to analyze the point of a computer screen at which the operator gazes while conducting a work, furthermore, a measuring method is employed in which physical viewpoint movement is recorded by a device such as an eye-mark-recorder and the movement is analyzed. In another method, the physiologic fatigue is measured after using a computer by a flicker test or the like. However, fatigue data which are collected in these methods remain simply as experimental data and are seldom reused as evaluation data for an actual design.
When summarizing the above-discussed problems, there are four problems in the prior art:
(1) In the prior art techniques using sketches, computer graphics, or the virtual reality, it is impossible to quantitatively evaluate an alternative of an arrangement of a workspace. Also, it is impossible to evaluate inconvenience, discomfort, and the like which are produced in an actual work.
(2) Models which are used in the field of the human factors are restricted to works which are conducted facing a computer, and therefore cannot be used to quantitatively evaluate an alternative of an arrangement of a workspace while considering all the works conducted in the whole workspace which include not only works conducted facing a computer but also document works conducted at the side of the computer, and works accompanied by movement of the body, and on the basis of differences in the body part size and in the standpoint of the operator.
(3) The analyzing technique is conducted on an operator in an existing workspace, and therefore cannot be applied to a workspace which will be created (or which does not exist). When an actual-size model of a workspace is produced and a motion analysis is conducted, experiments must be conducted on many subjects of various body sizes, and therefore it requires many labors and great expense. Furthermore, it is substantially impossible to conduct actual-size simulation on busy doctors, etc.
(4) Collected fatigue data are experimental data in any case, and cannot be used positively in an estimation of the fatigue, etc. due to the frequency and duration period of motions, because devices are arranged in different manner and the kinds of motions cannot be anticipated.